lacking the ability or skills to do something
the worst and most incompetent administration in living memory
completely/hopelessly/unbelievably incompetent: I am completely incompetent; can you show me that again?
incompetent at: The soldiers had four camels but were hopelessly incompetent at riding them.
mentally incompetent (=not able to make decisions because of a mental illness or lack of intelligence): Her attorney said she was not guilty because she was mentally incompetent.
Synonyms and related words